1. Field of the Invention
This invention generally relates to a bicycle pedal. More specifically, the present invention relates to a step-in or clipless type of bicycle pedal that engages a cleat in a releasable manner.
2. Background Information
Pedals are typically an essential bicycle component of most bicycles in that they transfer cycling power to the bicycle's drive train. Different styles of bicycles utilize different bicycle pedal styles that are designed for a specific purpose such as for pleasure, off road biking, road racing, etc. In recent years, step-in or clipless pedals have been gaining more popularity. The step-in or clipless pedal releasably engages a cleat that is secured to the sole of a rider's shoe. In other words, cleats are attached to the soles of specially-designed cycling shoes. The cleats lock the rider's feet into the pedals.
The step-in pedal typically has a pedal spindle that can be mounted on the crank of a bicycle, a pedal body that is rotatably supported on this pedal spindle, and at least one cleat engagement mechanism that clamps onto the cleat. In the case of off road bicycle pedals, typically both sides of the pedal body are provided with a cleat engagement mechanism for engaging a cleat in a releasable manner. On the other hand, in the case of road racing pedals, typically only one side of the pedal body is provided with a cleat engagement mechanism for engaging a cleat in a releasable manner. In either case, in using step-in or clipless types of bicycle pedals, the rider steps onto one side of the pedal body and the cleat engagement mechanism automatically grips on to the cleat that is secured to the bottom sole of the rider's shoe.
More specifically, in most cases, when attaching the rider's shoe to the step-in pedal via the cleat, the rider moves the shoe obliquely downwardly and forwardly relative to the pedal body such that the front end of the cleat engages a front hook or cleat engagement member of the pedal body. Once the front end of the cleat is engaged with the front hook of the pedal body, the rider places the rear end of the cleat in contact with a guide portion of the rear hook or cleat engagement member of the pedal body. In this position, the rider presses the shoe downwardly against the step-in pedal to cause the rear hook or cleat engagement member to initially pivot rearward against the force of a spring to move the rear hook or cleat engagement member to a cleat releasing position. The rear end of the cleat then enters a position opposite a back face of the rear hook or cleat engagement member. Then, the rear hook or cleat engagement member returns under the force of a biasing member or spring so that the rear hook or cleat engagement member engages the rear end of the cleat. This engagement fixes the rider's shoe to the step-in pedal via the cleat.
When releasing the shoe from most types of step-in pedals, the rider will typically turn the shoe about an axis perpendicular or approximately perpendicular to the tread of the rider's shoe, using the front end of the cleat as a pivoting point. As a result of this pivoting action, the rear cleat engagement member is pivoted rearward against the force of the spring to a cleat releasing position to release the shoe. Two examples of step-in pedals that operate in the above mentioned manner are disclosed in U.S. Pat. No. 6,845,688 and U.S. Pat. No. 6,446,529.
Of course, other types of step-in pedals have been proposed that operate in a slightly different manner. For example, U.S. Patent Publication No. 2010/0005924 discloses a step-in type of bicycle pedal in which the rear cleat engagement member is initially in a release position during a step-in operation. Also U.S. Pat. No. 6,164,158 discloses a step-in type of bicycle pedal in which a hydraulic circuit is used to move both front and rear cleat engagement members from initial released positions to engagement positions during a step-in operation.